The broadband access market, designed to provide voice, data and video (“triple play”) services to households and businesses, includes two major technologies, i.e. cable and digital subscriber line (DSL), and one up and coming challenger, i.e. fiber to the home (FTTH) or fiber to the curb (FTTC). Other minor players include satellite network solutions, e.g. Direct TV, and wireless solutions, e.g. WiMax. Each technology enables the customer's equipment to be connected to the internet, the telephone network, and the television/video service providers. In addition, a growing demand for extra services, such as voice over internet protocol (VoIP), internet protocol television (IPTV), video on demand (VoD), and online gaming have increased the demand for bandwidth and the necessity for operators to monitor their networks to ensure compliance with marketing claims.
With reference to FIG. 1, a typical local loop 1 is comprised of a digital subscriber line (DSL), a coaxial cable or an optical fiber for transmitting telephone, data and video signals to and from each customer premises equipment (CPE). Each CPE is comprised of a residential gateway (RG) or optical network terminal (ONT) 2, which is connected to one or more of the customer's telephone 4a, computer 4b and television 4c, via additional signal-specific CPE, e.g. a VoIP analog terminal adaptor (ATA) 6a, a modem 6b, and a set top box (STB) 6c, respectively. The ATA 6a, the modem 6b and the STB 6c can be built into the RG or ONT 2 or the customer's equipment 4a, 4b and 4c. The CPE 2 is connected to the internet 7 and/or corresponding communication networks via an access device or node 8a located in a central office 3 of the telephone company or cable provider, and a router or hub 9 located at an internet service provider 10.
DSL (digital subscriber line) is a broadband access technology that enables high-speed data transmission over existing copper telephone wires, which connect customer premises equipment (CPE) 2, e.g. a xDSL modem, to the local telephone company's central office 3. DSL technology is able to achieve a data rate of up to 52 Mbps by using advanced signal modulation technologies in the 25 kHz and 1.1 MHz frequency range in contrast to the conventional analog modem access, which is limited to a data rate of 56 Kbps at signal frequencies up to 4 kHz.
A Digital Subscriber Line Access Multiplexer (DSLAM) 8a is an access device at the phone company's central location 3 that links many customers DSL connections 1 to a single high-speed backbone line 11, e.g. asynchronous transfer mode (ATM), frame relay or Internet Protocol, and multiplexes the multiple signals into one combined signal 12. When the phone company receives a DSL signal from a customer, an asymmetric digital subscriber line (ADSL) modem 13 with a Plain Old Telephone Service (POTS) splitter detects voice calls and data. Voice calls are sent to the public switched telephone network (PSTN) 14, and data signals are sent to the DSLAM 8a. Each DSLAM 8a has multiple aggregation cards, and each such card can have multiple ports to which the customers lines are connected. Typically a single DSLAM aggregation card has twenty four ports, but this number can vary with each manufacturer. The most common DSLAMs are housed in a telco-grade chassis, which are supplied with (nominal) 48 volts using DC. Hence a typical DSLAM setup may contain power converters, DSLAM chassis, aggregation cards, cabling, and upstream links. The most common upstream links in these DSLAMs use gigabit ethernet or multi-gigabit fiber optic links.
A fibre optic node 8a in a cable or hybrid fiber-coaxial (HFC) network has a broadband optical receiver, which converts the downstream optically modulated signal coming from the hub 9 to an electrical signal going to the CPE 2. Today, the downstream signal is a radio frequency modulated signal that typically begins at 50 MHz and ranges from 550 MHz to 1000 MHz on the upper end. The fibre optic node (OLT) 8a also contains an upstream path transmitter that sends communication from the CPE 2 to the ISP 10. In North America, the upstream signal is a modulated radio frequency ranging from 5 to 42 MHz while in other parts of the world, the range is 5 to 65 MHz.
For fiber to the home or fiber to the curb networks, each node 8a includes an optical multiplexer for combining the signals from each local loop into a combined optical data signal.
The combined data signal 12 is passed through the high-speed line 11 to the hub 9 with an equipment management system (EMS) for the CPE's 2, e.g. a broadband remote access server (B-RAS) or Auto Configuration Server (ACS) for DSL, at the internet service provider (ISP) 10. The hub 9, authenticates the subscriber's credentials, validates the users access policies, and routes the data to respective destinations on the internet 7. For full triple play internet accessed services, signals are transmitted from the CPE's 2 via the internet 7 to video providers 18, and various other internet service providers 19. Alternatively, if the ISP 10 is also the video provider, an additional router is provided to route signals to and from the internet 7, and to and from video servers. Returning data signals from the internet 7 pass through the hub, 9, e.g. B-RAS, the node 8a, e.g. DSLAM, before returning to the customer premises equipment (CPE) 2.
The optical portion of HFC or FTTC networks provide a large amount of flexibility. If there are not many fibre optic cables to the hub 9, wavelength division multiplexing can be utilised to combine multiple optical signals onto the same fibre. Optical filters are used to combine and split optical wavelengths onto the single fibre. For example, the downstream signal could be on a wavelength at 1310 nm and the return signal could be on a wavelength at 1550 nm. There are also techniques to put multiple downstream and upstream signals on a single fibre by putting them at different wavelengths.
VoIP traffic is extremely sensitive to delay and jitter, while IPTV traffic is particularly sensitive to packet loss. Both video and VoIP traffic need to be prioritized against the data services with uneven and unpredictable bandwidth utilization. Accordingly, monitoring and validating the performance and quality of service of triple play ready networks and devices has become an issue of strategic importance for service providers and equipment manufacturers.
With millions of devices on existing networks, the challenge is to monitor all of the devices and provide a real time view of the network's health, while minimizing cost and overhead of processing hardware.
An object of the present invention is to overcome the shortcomings of the prior art by classifying the various devices into groups, and then monitoring the devices in dependence upon which group they are in.